* Fix TensorRT detection bug

1. Add new search path for TensorRT at tensorrt.cmake
2. Add better debug message
3. Fix the bug of detection of TensorRT version

In NVIDIA official docker image, TensorRT headers are located at
`/usr/include/x86_64-linux-gnu` and TensorRT libraries are located
at `/usr/lib/x86_64-linux-gnu`, so using `-DTENSORRT_ROOT` will
fail to detect TensorRT.

There is no debug/warning message to tell developer that TensorRT
is failed to be detected.

In later version of TensorRT (e.g. v6), `NV_TENSORRT_MAJOR` is
defined at `NvInferVersion.h` instead of `NvInfer.h`, so add
compatibility fix.

* Fix TensorRT variables in CMake

1. Replace `${TENSORRT_ROOT}/include` with `${TENSORRT_INCLUDE_DIR}`
2. Replace `${TENSORRT_ROOT}/lib` with `${TENSORRT_LIBRARY}`

Manually type path may locate incorrect path of TensorRT. Use the
paths detected by system instead.

* Fix TensorRT library path

1. Add new variable - `${TENSORRT_LIBRARY_DIR}`
2. Fix TensorRT library path

inference_lib.cmake and setup.py.in need the path of TensorRT library
instead of the file of TensorRT library, so add new variable to fix it.

* Add more general search rule for TensoRT

Let system detect architecture instead of manually assign it, so
replace `x86_64-linux-gnu` with `${CMAKE_LIBRARY_ARCHITECTURE}`.

* Add more general search rule for TensorRT

Remove duplicate search rules for TensorRT libraries. Use
`${TENSORRT_LIBRARY_DIR}` to get full path of libnvinfer.so

test=release/1.6

* fix the computation for dx (grad for x) for prelu operation. (#20949)

* set the default value of alpha for prelu to 0.25, test=develop

* add the call to __syncthreads(), test=develop

* fix the implementation of cpu prelu, test=develop

* repair the implementation of element mode prelu, test=develop

* modify test_prelu_op.py, test=develop

* fix fetch handler problem and refactor
when a user define FetchHandler class, he or she should initialize a handler
with variable dict. the key of a variable dict is a user defined name,
the value of a variable dict is a Varaible generated from python API.

For each fetching, a user should implement handler function in which
fetched_result_dict will be available and the user can access the fetched value
with user defined keys.

* disable reshape inplace in dygraph model; test=develop (#21157)

* fix ExecutionContext::HasInput and ExecutionContext::HasOutput depend on the scope structure, test=develop (#20721)

* set dim[0] to -1 if dim[0] < 0 and remove assertion to runtime, test=develop

* Improve argsort performance.

- Give 200000 data to compute argsort on v100,
can speed up ~190x
before opt cost: 0.53s
after opt cost:0.0027s

- Add fp16 support

* Refine error message
* Refine code
* Add descending sort

test=develop
Signed-off-by: Nzhaoyuchen <zhaoyuchen01@baidu.com>

* add Adam beta1/beta2 support Variable. test=develop

* Add Asypadding for conv fusion.

test=develop

reference: pr/20042

* Fix eigen build link error

* Change back file mode

* Use math function & add more checks.

* add the framework support for distfc and ut, test=develop
* fix the implementation of shard_index_op, test=develop

* batch_norm momentum support variable. test=develop

* support dump param of model into afs (#20302)

* support dump param to afs
test=develop

* code style
test=develop

* code style
test=develop

* dump param
test=develop

* dump param
test=develop

* dump param
test=develop

* dump param
test=develop

* find lookup table in order (#20932)

test=develop

* cherry-pick
test=develop

* solve pslib core in stop worker
test=develop

* print table stat info for pslib
test=develop

* fix cache table bug, add save_paddle_inference_model, fix hdfs util bug (#21052)

* fix cache table bug
* add save_paddle_inference_model
* fix hdfs util bug
* test=develop

* fix several sparse table issuses (#20686)

* no longer need to define all embedding layers (no one less) of all slots in each program. make trainer_param repeated in ps.proto.
* add find_distributed_lookup_table_grads instead of hard code GRAD
* support embedding stop gradient. push sparse has error before fix this.* 
* fix fill sparse, skip slots which do not have embedding. each slot's embedding in a sparse table should be used in all training programs before fix this.
* fix pull sparse, skip slots which do not have embedding.
* fix collect feasign label info, skip slots which do not have embedding.
* support when there are multi sparse tables in one or multi training programs, each program can pull/push its own related sparse tables instead of all sparse tables.
* test=develop

* add copy table (#21086)

* copy some feasigns and corresponding embeddings from one sparse table to another
* copy all feasigns and corresponding embeddings from one sparse table to another
* copy all dense params from one table to another
* copy some local vars to other local vars

* fix fs_client_param bug (#21212)

* fix fs_client_param bug， user can set this config through fleet_desc_file or fleet config
* test=develop

* fix fleet util bug (#21254)

* fix fleet util bug in save paddle inference model
* test=develop

* Fix gradients (#20857)

* fix_gradients

* fix_gradients, test=develop

* fix instance norm (#21042)

* fix instance norm

* update unitest,test=develop

* fix_bn

* revert unittest,test=develop

* add input type and input data type check for Print_op test=develop (#21250)

* add input type and input data type check for Print_op test=develop

* cherry-pick error info check of Print_op for release1.6 test=develop

* cherry-pick error info check of Print_op for release1.6 test=develop

* fix bug of issue #21259 (#21287)
pass the argument `allow_out_of_range` of one_hot op to c++ back end.

* [cherry-pick] All elements in attr(shape) of crop_tensor can be -1 and int32/64 kernel registered (#20756)

* All elements in attr(shape) of crop_tensor can be -1, test=develop, test=document_preview

* fix the bug that attr(offsets) should be initialized, test=develop

* [cherry-pick] maxout supports channel_last input (#20846)

* maxout support channel_last input, test=develop

* modified details of Input(X) and Attr(groups, axis) in doc, test=develop

* [cherry-pick] lrn supports channel_last input, test=develop (#20954)

* fix elementwise_mod FP kernel. test=develop

* fix unittest. test=develop

[cherry-pick]fix bug in pool/conv/conv_transpose: UpdatePaddingAndDilation, _get_padding_with_SAME and conv2dtranspose_forward_naive. (#20997) (#21225)

* fix bug in pool/conv/conv_transpose:
    1. It should be stride[i] not stride[0] in UpdatePaddingAndDilation;
    2. fix bug of func  _get_padding_with_SAME in test_conv/conv_transpose_op.py;
    3. fix bug of the computation process in function conv2dtranspose_forward_naive.
    test=release/1.6

test=release/1.6

TODO: fix cudnn_conv and re-enable it

test=develop
test=release/1.6

* Add asymetric padding support for mkldnn pooling
test=develop

* Add asymetric padding support for mkldnn conv
test=develop

* Add asymetric padding support for mkldnn conv_transpose
test=develop

* fix uniform random; test=develop

* add uniform random test; test=develop

* [cherry-pick]fix bug in reshape: (#20781)

consider the situation that shape of input can contain more than one -1.

* [cherry-pick]support Tensor for split and concat, support -1 in num_or_sections, add check num_or_sections (#20780)

* improve split and concat op:
1. support Tensor for argument 'dim' in split op.
2. support Tensor for argument 'axis' in concat op.
* redefine function GetDataFromTensor and set unknown output shape to - 1.
* add check: Attr(sections) match Input(X).
* support Tensor for attr(sections) and attr(sections) can contain -1.
* modify error message and fix bug for concat and call Resize only when necessary.
test=release/1.6

* [cherry-pick]improve unsqueeze op to support int, Tensor for argument axes (#20824)

* improve unsqueeze op to support int, Tensor and Tensor list for argument axes.
* call Resize only when necessary. test=release/1.6

* [cherry-pick]Compatible int32 and int64 for attr in concat/split/unsqueeze. test=release/1.6 (#20912)

cherry-pick1.6 simplify master+patch，remove ins when size != merge_size or has conflict slot  (#20941)

* simplify master+patch，remove ins when size != merge_size or has conflict slot
* test=develop

* add check nan / inf in downpour worker during training
* test=develop

* update pserver decay blocks

* update distributed notify handler

[cherry-pick] keep the size of symmetric padding is 2 for 2d and 3 for 3d. test=release/1.6 (#20903) (#20939)

* Fix Paddle Cloud role maker (#20860)